ᐅ Shaft well for heat pump, underfloor heating in a single-family house, heat pump for domestic hot water

[TD="class: alt1, bgcolor: #F5F5FF"]Hello everyone,

we are currently planning the heating system for our new build.
Our plot borders directly on a river (Fuhse).

We are considering digging a shaft well with concrete rings about 2-3 meters (7-10 feet) before the end of the property toward the Fuhse and filling it with gravel.
Then, we would excavate a type of gravel bed from the riverbank to the well and subsequently refill it with soil, so that the river water can flow through this gravel bed year-round to the well.

At the bottom of the well, a pump would be installed to transport the water to the house’s heat exchanger, where it would be heated for underfloor heating and domestic hot water.
After passing through the heat exchanger, the water would return through the garden back to the Fuhse, or into the groundwater.

My question to the experts:

Does this type of heat pump make sense?
The costs would be quite manageable, and the water’s energy would presumably be ideal considering heat conductivity?

Thank you in advance and best regards,
Marcel

Hello,

Schulle84 schrieb:
.., so that the Fuhse water can reach the well throughout the year in this gravel bed.

How is it ensured how the water (how much?) is permanently supplied and also safely drained (soakaway well)? Water quality?

Schulle84 schrieb:
.....Does this type of heat pump make sense?

In principle, it is a domestic hot water heat pump.

Schulle84 schrieb:
...and the energy of the water would be the best when it comes to thermal conductivity, right?!

Water is not used without reason (specific heat capacity) predominantly as a carrier medium. A very good energy reservoir and transporter. One should not forget that energy (how much?) is extracted => temperature drop. It is no coincidence that closed systems (surface collector, vertical borehole, trench collector) are mixed with antifreeze! This is probably not possible with this open system.;) So first have the demand calculated, then clarify the rest. Best regards

Since the shaft is located very close to the river and the gravel bed is very deep (almost at riverbed level), continuous water supply should be ensured.

There should be no direct injection well; the water on its return from the heat exchanger is either fed back into drainage pipes to be used for garden irrigation or directed back towards the river/groundwater.

Unfortunately, I cannot currently comment on the water quality. Is it really that important for river water?

Regarding frost protection:
Since the shaft is supposed to be deep underground and the pipes running through the soil to the house (heat exchanger), I believe this serves as a form of frost protection.